2002 Annual

Wednesday, 16 January 2002: 2:45 PM
Early results from the Global Atmospherics, Inc. Dallas-Fort Worth Lightning Detection and Ranging (LDAR-II) research network
Nicholas W. S. Demetriades, Global Atmospherics, Inc., Tucson, AZ; and M. J. Murphy and K. L. Cummins
Global Atmospherics, Inc. recently installed a regional Lightning Detection and Ranging (LDAR-II) network for research purposes in the vicinity of Dallas-Fort Worth (DFW) International Airport. This network became fully operational on 1 March 2001. The DFW LDAR-II network is made up of 7 sensors, with 20 to 30 km baselines, that can detect pulses of radiation produced by the electrical breakdown processes of lightning in a 5-MHz band within a subset of the VHF (50-120 MHz) band. This regional LDAR-II network can map lightning flashes in 3-dimensions within approximately 150 km of the center of the network, degrading in performance with increasing range. Lightning flash detection efficiency is greater than 99% within the interior of the DFW LDAR-II network (a range of 30 km from DFW International Airport) and greater than 90% out to a range of 150 km from DFW International Airport. Three-dimensional location accuracy for individual pulses of radiation is better than 100 m within the interior of the network and better than 2 km to a range of 150 km from the network center.

Early analysis of the DFW LDAR-II network has involved comparisons of LDAR-II data with the U.S. National Lightning Detection Network (NLDN) and radar base reflectivity images from the DFW National Weather Service (NWS) radar. The results of these comparisons will be summarized for a variety of thunderstorm cases including squall-lines and pulse-type storms. Comparisons have also been made with a test network of low-frequency (LF) lightning detection sensors in the DFW area that detects cloud lightning with low detection efficiencies. Specifically, cloud lightning flash data rates from both networks were examined for a few case studies involving small time segments of data. Preliminary results of these studies will be presented in this paper.

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